Summary: Sierra launched Ghostwriter last month — an AI Agent that creates other AI Agents. At the HumanX conference, founder Bret Taylor declared that employees will no longer need to learn how to operate enterprise software — they can simply describe what they need in natural language and the AI handles the rest. Sierra, founded less than two years ago, already exceeds $100M in ARR and carries a $10B valuation.
One Sentence to Replace an Application
Sierra’s founder and CEO Bret Taylor had a clear take on the future of software interaction: the era of clicking buttons is ending.
Taylor previously served as co-CEO at Salesforce. Sierra is focused on building customer service AI Agents for enterprises. Last month, the company launched Ghostwriter — an “Agent that builds other Agents.” The tool operates on an “Agent as a Service” model, replacing traditional click-based web applications with natural language interfaces. Users simply describe what they want, and Ghostwriter autonomously creates and deploys a dedicated Agent to execute the task.
At HumanX, Taylor used enterprise HR systems as an example: “When you join a company, you log into Workday, create an account, fill in information, and then probably don’t touch it again until it’s time to sign up for something.” Instead of spending time learning complex systems, employees will soon complete tasks directly through natural language — without ever touching the software interface.
“I think the world is just going to go that direction,” Taylor said.
Speed as Proof of Concept
Taylor said Sierra has already validated Ghostwriter’s deployment capability in practice. He cited retail giant Nordstrom as an example — the entire Agent went live in just four weeks.
Sierra’s growth rate is rare in the industry. Last fall, the company announced it crossed $100M in Annual Recurring Revenue, less than 21 months after founding. In September 2024, Sierra raised $350M in a round led by Greenoaks Capital, reaching a $10B valuation.
“Most companies don’t want to build software,” Taylor said. “They want the problem solved.”
The Reality: AI Agents Still Need Work
While Taylor’s vision of the future of software interaction is compelling, tech investors and experts caution that actual AI Agent deployment is far less automated than the marketing suggests.
Companies including Sierra and legal AI startup Harvey, which claim to offer AI Agent services, still rely heavily on “forward-deployed engineers” — engineers who continuously tune and adjust each Agent to client-specific needs to ensure proper operation. In other words, the degree of “autonomy” is still a significant discount from the ideal.
This highlights a core tension: if AI Agents still require substantial human intervention to function properly, is the promise of “replacing click-based applications” truly advantageous in time and cost?
The Bigger Picture: Software Interfaces May Face Reinvention
Regardless of whether AI Agents achieve full autonomy in the short term, the direction Taylor is pointing at deserves serious attention. For two decades, enterprise software design logic has been “teach users to operate the interface.” If the future becomes “let the interface learn to understand user intent,” the entire software industry architecture needs rethinking.
Enterprise software giants like Workday, Salesforce, and SAP have accumulated decades of interface design experience and user habits. But AI Agents are precisely aimed at making these interfaces irrelevant. For software incumbents, this is both a threat and a trend they cannot ignore.
Sierra currently focuses on customer service, but Ghostwriter’s design clearly targets broader enterprise applications. When the loop of “describing a need in language → AI autonomously creates a solution” is validated, the click-based software doesn’t just face a competitor change — it faces a challenge to its entire reason for existence.
Source
- Original: Sierra’s Bret Taylor says the era of clicking buttons is over — Marina Temkin, TechCrunch (2026-04-09)
